692 BUI.LETIN 83- 



branches, they measured about i mm (.04 of an inch) in length, 

 or were only about twice as large as when they hatched and went 

 onto the leaves in July. These small dark brown scales are at 

 present on the trees in the position to which they migrated in 

 September. They will doubtless pass the winter in this stage, 

 without feeding. Many of these hibernating scales are shown in 

 figure I ; they lie scattered about on the plum branch among a 

 few old mother shells. 



It is to these hibernating scales that we referred when we stated 

 on a preceding page that there are at the present moment more 

 than 50,000 of the best plum trees in western New York, each of 

 which is harboring millions upon millions of this Plum Scale. 

 Fortunately, these hibernating scales are tender creatures, and 

 most of them lie exposed on the bark of the trees. Thus this 

 stage is the weakest point in their life history, and fruit growers 

 must take advantage of it this winter. For, as we have shown 

 above, these little creatures grow witli astonishing rapidity early 

 in the spring and soon get beyond man's power to check them by 

 any practicable means. 



N2iinber of broods. — There is but one brood in a year. The 

 little scales now in hibernation develop into full grown males and 

 females in May. Eggs are soon laid, and this stage lasts nearly a 

 month. About July i , the young scales emerge and migrate to 

 the leaves where they remain for two or three months, scarcely 

 doubling in size meantime. In September these scales again mi- 

 grate, going onto the branches where they hibernate. 



HOW THE INSECT SPREADS. 



As the pest is not very active in any of its stages, it doubtless 

 would spread very slowly if left to itself At certain seasons, how- 

 ever, especially when the young scales are migrating in July and 

 September, many of them doubtless become attached to the feet of 

 birds that may then visit the trees. The scales could be carried 

 long distances in this way. 



The young scales may also attach themselves to larger 

 insects which frequent the trees. East year, in Maryland, several 

 Eady-bird beetles and ants were seen bearing one or more young 



